ohh I see now, I didn't read it all, I just looked at the picture and I saw a connector the goes to your computer so I thought it went like this Main PSU>Supplementary PSU>Graphics Card. Not Wall>PCI Slot>Supplementary>Graphics. I didn't even notice the pci slot. I see how it works now.

Yea, it uses its own power to power the graphics cards and you can save spending money on a badass PSU to power your SLI. I might actualy get this to power my single X1900XTX instead of buying a whole new PSU for my system. Think it will work?